Also forgot to mention , beware of spruikers with you beaut courses and software that promise the earth and deliver nothing. (Caveat Emptor)
If you are interested in articles re the spi, you could try back issues of your trading edge magazine.There are some great people who write for them who I've had dealings with over the years who are very knowledgeable as well as street smart in such areas with proven track records rather than fly by nighters.
Once again you need to be discerning and also comfortable with whoever you are dealing with , if you decide to further your experience & knowledge in such areas.
